[alsa-devel] [PATCH v2] ASoC: AMD: Fix capture unstable in beginning for some runs
alsa_conformance_test -C hw:0,4 -p 1024 --debug would sometime show: TIME_DIFF(s) HW_LEVEL READ RATE 0.000095970 1024 1024 10670001.041992 0.042609555 1024 2048 24032.168372 0.021330364 1024 3072 48006.681930 0.021339559 1024 4096 47985.996337 The issue is that in dma pointer function we can have stale value of the register for current descriptor of channel. The register retains the number of the last descriptor that was transferred.
Fix ensures that we report position, 0, till the one period worth of data is transferred. After one period of data, in handler of period completion interrupt we update the config and correct value of descriptor starts reflecting.
Signed-off-by: Akshu Agrawal akshu.agrawal@amd.com
--- v2: fix overrun issue and missed case where bytescount = rtd->bytescount sound/soc/amd/acp-pcm-dma.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-)
diff --git a/sound/soc/amd/acp-pcm-dma.c b/sound/soc/amd/acp-pcm-dma.c index b0e245c..0ac4b5b 100644 --- a/sound/soc/amd/acp-pcm-dma.c +++ b/sound/soc/amd/acp-pcm-dma.c @@ -1035,16 +1035,22 @@ static snd_pcm_uframes_t acp_dma_pointer(struct snd_pcm_substream *substream)
if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) { period_bytes = frames_to_bytes(runtime, runtime->period_size); - dscr = acp_reg_read(rtd->acp_mmio, rtd->dma_curr_dscr); - if (dscr == rtd->dma_dscr_idx_1) - pos = period_bytes; - else - pos = 0; bytescount = acp_get_byte_count(rtd); - if (bytescount > rtd->bytescount) + if (bytescount >= rtd->bytescount) bytescount -= rtd->bytescount; - delay = do_div(bytescount, period_bytes); - runtime->delay = bytes_to_frames(runtime, delay); + if (bytescount < period_bytes) { + pos = 0; + } else { + dscr = acp_reg_read(rtd->acp_mmio, rtd->dma_curr_dscr); + if (dscr == rtd->dma_dscr_idx_1) + pos = period_bytes; + else + pos = 0; + } + if (bytescount > 0) { + delay = do_div(bytescount, period_bytes); + runtime->delay = bytes_to_frames(runtime, delay); + } } else { buffersize = frames_to_bytes(runtime, runtime->buffer_size); bytescount = acp_get_byte_count(rtd);
The patch
ASoC: AMD: Fix capture unstable in beginning for some runs
has been applied to the asoc tree at
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git
All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying to this mail.
Thanks, Mark
From c50535ed6a10fcae1b64ae83c0f6b1eeb5535afc Mon Sep 17 00:00:00 2001
From: Akshu Agrawal akshu.agrawal@amd.com Date: Tue, 18 Sep 2018 12:53:13 +0530 Subject: [PATCH] ASoC: AMD: Fix capture unstable in beginning for some runs
alsa_conformance_test -C hw:0,4 -p 1024 --debug would sometime show: TIME_DIFF(s) HW_LEVEL READ RATE 0.000095970 1024 1024 10670001.041992 0.042609555 1024 2048 24032.168372 0.021330364 1024 3072 48006.681930 0.021339559 1024 4096 47985.996337 The issue is that in dma pointer function we can have stale value of the register for current descriptor of channel. The register retains the number of the last descriptor that was transferred.
Fix ensures that we report position, 0, till the one period worth of data is transferred. After one period of data, in handler of period completion interrupt we update the config and correct value of descriptor starts reflecting.
Signed-off-by: Akshu Agrawal akshu.agrawal@amd.com Signed-off-by: Mark Brown broonie@kernel.org --- sound/soc/amd/acp-pcm-dma.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-)
diff --git a/sound/soc/amd/acp-pcm-dma.c b/sound/soc/amd/acp-pcm-dma.c index 77b265bd0505..3135e9eafd18 100644 --- a/sound/soc/amd/acp-pcm-dma.c +++ b/sound/soc/amd/acp-pcm-dma.c @@ -1036,16 +1036,22 @@ static snd_pcm_uframes_t acp_dma_pointer(struct snd_pcm_substream *substream)
if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) { period_bytes = frames_to_bytes(runtime, runtime->period_size); - dscr = acp_reg_read(rtd->acp_mmio, rtd->dma_curr_dscr); - if (dscr == rtd->dma_dscr_idx_1) - pos = period_bytes; - else - pos = 0; bytescount = acp_get_byte_count(rtd); - if (bytescount > rtd->bytescount) + if (bytescount >= rtd->bytescount) bytescount -= rtd->bytescount; - delay = do_div(bytescount, period_bytes); - runtime->delay = bytes_to_frames(runtime, delay); + if (bytescount < period_bytes) { + pos = 0; + } else { + dscr = acp_reg_read(rtd->acp_mmio, rtd->dma_curr_dscr); + if (dscr == rtd->dma_dscr_idx_1) + pos = period_bytes; + else + pos = 0; + } + if (bytescount > 0) { + delay = do_div(bytescount, period_bytes); + runtime->delay = bytes_to_frames(runtime, delay); + } } else { buffersize = frames_to_bytes(runtime, runtime->buffer_size); bytescount = acp_get_byte_count(rtd);
participants (2)
-
Akshu Agrawal -
Mark Brown